1. By: –Brian Ambrosini –Matt Spence –Waldon Wong Engineering 45 Younes Ataiiyan Santa Rosa Junior College 12/06/04

2. Applications Circuit Boards Circuit Boards Connecting copper pipes Connecting copper pipes Light bulbs Light bulbs Alternators 1 Alternators 1 Stained Glass Stained Glass

3. Soldering Techniques & Future Products Soldering Iron Soldering Iron Blow Torch Blow Torch Solder Wave Machine Solder Wave Machine Cold Heat 2 Cold Heat 2

4. ExperimentExperiment Procedure Experiment Cut up solder Cut up solder Heat solder in crucible Heat solder in crucible Cool Cool –Slowly cool in furnace (100°F/20 min) –Air Cooled –Ice cooled

5. Procedure Continued Cast the cooled solder in plastic Cast the cooled solder in plastic –Bakelite would melt the solder (thanks Younes) Sand and Polish sample Sand and Polish sample Etch with Nitric acid Etch with Nitric acid View/compare microstructure View/compare microstructure

6. Lead-Tin Phase Diagram 3

7. Results – Ice Cooled Small eutectic structures (dark areas) Small eutectic structures (dark areas) Less ductile then the other specimens 4 Less ductile then the other specimens 4 Most susceptible to fatigue Most susceptible to fatigue –Possible reduction in life

8. Results – Air Cooled Standard sized eutectic structure (dark areas) Standard sized eutectic structure (dark areas)

9. Results – Slow Cooled Large eutectoid structures (dark areas) Large eutectoid structures (dark areas) –By cooling the sample slowly, it looks similar to steel Most ductile sample Most ductile sample –Best commercial use –Not cost effective

10. Conclusions Air cooled specimen had a medium amount of eutectic structures Air cooled specimen had a medium amount of eutectic structures The furnace cooled specimen had large eutectic structures The furnace cooled specimen had large eutectic structures –More ductile –Not as strong Ice cooled specimen had very small eutectic structures Ice cooled specimen had very small eutectic structures –Less ductile (more brittle) All three samples have the same composition All three samples have the same composition –Electrical properties are similar

11. References 1: http://www.seas.ucla.edu/eThinFilm/Pb- freeWorkshop/abs/pan.html 1: http://www.seas.ucla.edu/eThinFilm/Pb- freeWorkshop/abs/pan.htmlhttp://www.seas.ucla.edu/eThinFilm/Pb- freeWorkshop/abs/pan.htmlhttp://www.seas.ucla.edu/eThinFilm/Pb- freeWorkshop/abs/pan.html 2: http://www.coldheat.com/ 2: http://www.coldheat.com/http://www.coldheat.com/ 3: http://www2.umist.ac.uk/material/research/intmic/phase/pbsn diag.htm 3: http://www2.umist.ac.uk/material/research/intmic/phase/pbsn diag.htm http://www2.umist.ac.uk/material/research/intmic/phase/pbsn diag.htm http://www2.umist.ac.uk/material/research/intmic/phase/pbsn diag.htm 4: http://technology.open.ac.uk/emsuite/prj7.html 4: http://technology.open.ac.uk/emsuite/prj7.htmlhttp://technology.open.ac.uk/emsuite/prj7.html